Folding ladder

ABSTRACT

A folding ladder is disclosed which has one end securely fastened to a structure and is stored therein. Said ladder is extendible along a wall of said structure to allow an emergency egress therefrom. The ladder is comprised of sections, each section having a rung and a pair of handrail sections. Further, every other section includes a stand-off member to engage the wall of the structure thereby providing stability. When not in use, the ladder sections are foldable to stack one section on the other thereby forming a compact package for storage.

[ Sept. 23, 1975 FOREIGN PATENTS OR APPLICATIONS 259,297 6/1949 Switzerland.........................182/164 Primary ExaminerRobert L. Wolfe Assistant ExaminerDavid H1. Corbin Attorney, Agent, or FirmWood, Harron & Evans [57] ABSTRACT A folding ladder is disclosed which has one end securely fastened to a structure and is stored therein. Said ladder is extendible along a wall of said structure to allow an emergency egress therefrom. The ladder is comprised of sections, each section having a rung and a pair of handrail sections. Further, every other sec- Thomas 13. Kennedy, 3175 Pickbury Dr., Cincinnati, Ohio 45211 Dec. 17, 1973 U.S. 1182/16 1 Int. E06C l/38 Field 01Search....... 182/70, 76, 163, 164, 197, 182/198, 228

References Cited UNITED STATES PATENTS Elnited States Patent [191 Kennedy 4] FOLDING LADDER [76] Inventor:

[22 Filed:

211 App1.N0.:4125,1)67

"nu" "I nun Hmmmmmm I "S u 1 mm WW m mmm m a o hko FDBDLKRH 7 7 9 30 79900667 8000099999 11111111 8204374 1 US Patent Sept. 23, 975

FOLDING LADDER BACKGROUND OF THE INVENTION The invention relates generally to folding ladders and specifically the invention provides a folding ladder which is anchored to a fixed location for emergency use and may be stored in a relatively compact mode.

There are a great variety of types of folding ladders shown in the prior art. One type of ladder contains flexible components, e.g. rope rungs. These ladders are very unstable and require great physical strength in use. Another type of ladder contains rigid components, but these components are not rigidly connected to each other. Consequently, these ladders have excessive side to side motion and are difficult to use.

The prior art contains further types of folding ladders having unprotected joints in the handrails or side members. These unprotected handrail joints may cut or pinch the hands of a user which is dangerous in an emergency. Other prior art ladders contain rungs which are not supported away from the structure to facilitate use. Further, other ladders only have a relatively few widely spaced points of support and again are very unstable. Finally, in addition to the above disadvantages, many of the prior art ladders have a relatively complicated construction which makes them expensive to manufacture thereby severly restricting the possibility of commercial exploitation.

Applicant discloses a foldable ladder having rigid components which are rigidly connected together into ladder sections thereby minimizing sideward movement of the ladder. The ladder contains smooth straight handrails in relatively straight alignment, and the joints between the handrail sections are guarded thereby minimizing interference. Further, every other section of the ladder contains a standoff member for maintaining the ladder away from the structure thus facilitating use. Finally, the ladder construction is such that it may be economically manufactured and marketed.

SUMMARY OF THE INVENTION further contains a plurality of second sections, each second section being pivotally connected between two of the first sections to form a chain of alternate first and second sections. Each second section contains a pair of second elements having a closed loop configuration and a second cross member connected therebetween.

The second cross member is operative to maintain the second elements approximately parallel with a predetermined distance therebetween. The ladder further includes means connected between the chain of sections and the structure for securing said chain of sections to said structure.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates applicants ladder in its extended mode.

FIG. 2 is a front view of one of the two basic ladder sections.

FIG. 3 is a side view of the ladder section shown in FIG. 2.

FIG. 4 is a front view of the other of the two basic ladder sections.

FIG. 5 is a side view of the ladder section shown in F IG. 4.

FIG. 6 illustrates how applicants ladder may be folded for storage.

FIG. 7 is an exploded view illustrating a typical joint assembly between two of the ladder sections.

FIG. 8 illustrates a typical connection between one of the flexible ladder members and the anchor plate which is securely fastened to the structure.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates applicants ladder in the extended mode. FIG. 1 shows only one example of each of the basic sections comprising the ladder. The heart of the ladder is contained in a first section 10 and a second section 12. The ladder can be made to any desired length by using the appropriate number of first and second sections.

FIGS. 2 and 3 illustrate orthogonal projections of the first section 10. Each first section is comprised of a pair of first elements or side rails 14 and 16 and a primary cross member 18. The section 10 also contains a second cross member 19; however, as will be subsequently discussed, this member is not a necessary ladder element. The elements 14 and 16 have similar configurations with the element 16 being the mirror image of the element 14. Each element is comprised of an inflexible piece having first and second offsets 26 and 28, respectively. Further, each first element has one end curved to form a loop 30 offset from the centerline 31, and the other end is rigidly connected, e. g. welded, between the cross members 18 and 19.

FIGS. 4 and 5 illustrate orthogonal projections of the second section 12. Each second section is comprised of a pair of second elements 20 and 22 and a primary cross member 24. As with the first section, the second section also contains a secondary cross member 25. The second element 20 is comprised of first and second inflexible pieces 34 and 36, and the second element 22 is comprised of the inflexible pieces 38 and 40. With the exception of the pieces 36 and 40, the second section shown in FIG. 4 is identical to the first section shown in FIG. 2. Each of the first pieces or side rails 34 and 38 contain first and second offsets 42 and 44. Further, each first piece is curved at one end to form a loop or eye 46 offset from the centerline 47 and is rigidly connected at the other end between the cross members 24 and 25.

Each of the second pieces 36 and 40 are generally configured to form a closed loop or eye with each of the first pieces 34 and 38, respectively. Referring to FIG. 5 in the preferred embodiment, each second piece is comprised of a straight base portion 48 with two side portions 50 and 52 extending from the base and forming obtuse included angles therewith. The base 48 provides a bearing surface against the wall of a structure thereby substantially increasing the stability of the ladder. While the ladder is being extended, the general configuration of the two pieces 36 and 40 allow the ladder to slide over any obstructions along the wall, e.g.

trim pieces, drain pipe, etc. The ends of each second piece are rigidly connected to the first piece.

Referring back to FIG. 1, the first and second sections and 12 are connected by a pair of pivotal joints shown at 54 and 56. A typical pivotal joint is shown in an exploded view in FIG. 7 and is formed by the closed loop 46 and the cross member 18. In the preferred embodiment, both ends of all the primary cross members are threaded. Each joint is comprised of a shoulder bushing located on the member 18 adjacent to the closed loop 46 and provides a bearing surface for the rotation of the loop 46. A spacer 62 is located on the member 18 between the closed loop 46 and a locking nut 64 which is threaded on the member 18. All of the pivotal joints between the ladder sections are identical to the typical joint shown in FIG. 7.

At this point a number of advantages of applicants ladder should be apparent. The elements 14, 16, 34 and 38, which function as handrails, are smooth straight and in line with each other. These elements are very functional and do not cause any problems in use. The offsets on the handrail portions maximize the ladder width and also operate to guard the pivotal joints. Therefore, the pivotal joints should not interfere either with the extension of the ladder or with actual ladder use. Further, the elements 36 and 40, which function as stand-off portions maintain the ladder a predetermined distance away from the structure and allow the user to obtain an adequate foothold on the ladder. Finally, the rigidly connected ladder pieces increases the overall stability of the ladder and minimize side to side motion when in use.

In addition to the two basic ladder sections 10 and 12, the preferred embodiment of the ladder contains two transition sections a bottom section 66 and a top section 68. The bottom section 66 is similar to the second section 12 with two exceptions. The primary exception is the addition of a handle 70 which facilitates lifting the ladder from the stored mode to initiate extension. The handle may be connected to the bottom section by any well known technique. However, in the preferred embodiment, the handle 70 is part of a single inflexible piece which includes the handrail portions 72 and 74 of the bottom section. Since, by definition, the bottom section does not require a pivotal joint, the primary cross member does not contain threaded end por tions. Instead the primary cross member is part of a single inflexible piece which includes the standoff portions 76 and 78.

The top section 68 contains two handrail members 80 and 82 and primary and secondary cross members (not shown). One end of the handrail members contains offsets identical to the offsets 28 of the elements 14 and 16. Further, the handrails 80 and 82 are connected to the cross members in a manner identical to that as described for the first section 10 and shown in FIGS. 2 and 3.

Associated with the top section 68 are two flexible members 86 and 88. These members may be made of flexible cable, chain or any other flexible material providing the desired strength. Further, the flexible members may be connected to the elements 80'and 82 by any well known means. In the preferred embodiment, applicants have chosen chain as the flexible member. The elements 80 and 82 contain closed loops 90 and 92. The closed loops engage the first link in each of the chain members. Further, a rigid element 94 is connected between the elements 80 and 82 for stability. The other end of each chain member is connected to an anchor plate 96 shown in FIG. 8.

The anchor plate 96 has two approximately perpendicular sides and is of sufficient length to permit each flexible cross member to be connected thereto. As shown in FIG. 8, a typical connection is made with a U- shaped member 98 which is rigidly connected to the anchor plate 96. A pin 100 passes through the member 98 and the last link of the flexible chain member 88 thereby securing the flexible member to the anchor plate. As shown in FIG. 6, the anchor plate 96 is securely fastened to a wall and a floor of the structure directly below a window or other opening. Further, in the preferred embodiment, the anchor plate is shaped such that it does not interfere with a toe strip 102.

FIG. 6 also illustrates how the configuration of the stand-off members of brackets or each of the second sections allows the ladder to fold into a relatively compact package without interference from said members. It should also be noted that in folding the ladder each first section pivots in one direction while each second section pivots in the opposite direction. The construction is such that the ladder folds only one way; and when folding, each section readily drops into its proper position.

The primary cross member of each section has a covering typically shown in FIG. 7. The covering contains a flat tread surface and is rigidly connected to the primary cross member. In the preferred embodiment, the covering is typically comprised of two half sections 104 and 106. Further, each half section is hollowed out such that the halves of the covering fit together over the primary and secondary cross members. Fasteners typically comprised of a screw 108 and a nut 110 pass through each half of the covering, as well as between the primary and secondary cross members. Consequently, the fasteners hold the halves of the covering together and prevent relative motion between the covering and the cross members.

In the preferred embodiment, the side elements and cross members of each section are constructed of a cylindrical wire rod material. However, any rod-like material which is of sufficient strength can be used.

While the invention has been illustrated in some detail according to the preferred embodiments shown in the accompanying drawings, and while the preferred illustrated embodiments have been described in some detail, there is no intention to thus limit the invention to such detail. On the contrary, it is intended to cover all modifications, alterations and equivalents falling within the spirit and scope of the appended claims.

What we claim is:

I.,A ladder foldable for storage inside a building and extendible along a wall of said building to permit egress therefrom, the ladder comprising:

a. a plurality of rigid first sections, each first section including a pair of first elements and a first cross member, each first element having I. an eye at a first end,

2. the other end of each first element being joined to said first cross member, which maintains said first elements approximately parallel to one another at a predetermined spacing therebetween,

3. a first offset extending a predetermined inward distance at said other end, said first element being joined to said first cross member through this offset, and I 4. a second offset at said first end of said first element, said second offset extending inwardly a different distance than the first offset;

b. a plurality of rigid second sections, each second section including a pair of second elements and a second cross member, said second element including 1. a first piece having an eye at a first end and having the other end joined to the second cross member which maintains said second elements approximately parallel to one another at said predetermined spacing therebetween, the length of said first piece being approximately equal to the length of said first element,

a first offset extending a predetermined inward distance at said other end of said first piece, said first piece being joined to said second cross member through this offset, this offset being approximately equal to the first offset of the first element, and a second offset at said first end of said first piece, the magnitude thereof being approximately equal to the second offset of said first element, and

2. a second piece rigidly connected to the first piece, said second piece having a base for engaging the wall of said building and providing a bearing surface thereagainst, and two sides, the sides forming obtuse angles with said base and being rigidly connected to the first piece;

c. alternate first and second sections being connected together as a chain of sections by first and second pairs of pivoted connections, the eyes of the first pieces of second sections receiving the first cross members of first sections to form the first pairs of pivoted connections, the eyes of the first elements receiving the cross members of second sections to form the second pairs of pivoted connections;

d. said first and second cross members comprising inflexible pieces having lengths approximately equal to the predetermined spacings between the respective pairs of elements;

e. covering means rigidly connected to and covering each respective cross member, said covering means having a tread surface providing a ladder step, said covering means comprising 1. a supporting member rigidly connected to the respective pair of elements, parallel to the cross member therebetween but spaced from the cross member by a gap,

2. a covering member hollowed out for receiving the supporting member and the adjacent cross member, and

3. fastening means passing through said gap and rigidly connecting the covering member to the respective section, and

f. means for securing the chain of sections to said building.

2. The ladder of claim 1 wherein the securing means comprises:

a. a pair of flexible members;

b. means for connecting one end of each of the flexible members to the building; and

c. means for connecting the other end of each of the flexible members to one end of the chain of sectrons.

3. The ladder of claim 2 wherein said flexible members are comprised of two equal lengths of chain.

4. The ladder of claim 3 wherein the means for connecting one end of the flexible members to the building 5 comprises:

a. an anchor plate having at least two sides approximately perpendicular to one another to permit said sides to be connected to two surfaces of said building; and

b. means rigidly connected to said plate for accepting one link of each of said chains thereby securing said chains to the plate.

5. The ladder of claim 4 wherein the other end of the chain of sections includes a handle rigidly connected thereto.

6. The ladder of claim 5 wherein all the first and second elements, the cross members and the handle are formed of a wire rod material.

7. A ladder foldable for storage inside a building and extendible along a wall of the building to permit egress therefrom, the ladder comprising:

a plurality of generally U-shaped sections, each section including two parallel side rails which are spaced apart a predetermined distance by a cross member that is connected between them, each side rail having a longitudinal axis and two ends,

each side rail having an inward offset adjacent each end thereof which positions the respective rail end inwardly of the longitudinal axis of the rail,

the cross member of each section being secured to first ends of the rails respective of the section, inwardly of the longitudinal axes thereof, the cross member being no longer than the predetermined distance by which said rails are spaced,

the other end of each rail presenting an eye, the eye being positioned inwardly of the longitudinal axis of the rail by the offset adjacent said other end,

the inward offsets of the respective ends being of different inward extents,

each eye having a center which is offset perpendicularly from the plane of said U-shaped section,

said sections being connected together serially to form a chain, the cross member of each section being pivotally journalcd in the eyes of the next adjacent section,

the distance between the side rails being the same for all sections so that the longitudinal axes of the pairs of side rails of the respective sections are substantially colinear with one another when the ladder is extended,

the pivotal connections between adjacent sections lying inwardly of the axes of the rails by reason of said inward offsets,

each said section in the chain being so oriented that when the ladder is extended the eyes of the rails thereof are offset perpendicularly in the opposite direction from the eyes of the rails of the adjacent section,

every other section of said chain having a standoff bracket which is connected to the side rails thereof. each standoff bracket having a base for engaging the wall of said building and for providing a bearing surface thereagainst, and two sides, the sides forming angles with the base and being rigidly connected to respective rail inwardly of the longitudinal axis thereof,

and means for hanging the chain of sections from said building. 

1. A ladder foldable for storage inside a building and extendible along a wall of said building to permit egress therefrom, the ladder comprising: a. a plurality of rigid first sections, each first section including a pair of first elements and a first cross member, each first element having
 1. an eye at a first end,
 2. the other end of each first element being joined to said first cross member, which maintains said first elements approximately parallel to one another at a predetermined spacing therebetween,
 3. a first offset extending a predetermined inward distance at said other end, said first element being joined to said first cross member through this offset, and
 4. a second offset at said first end of said first element, said second offset extending inwardly a different distance than the first offset; b. a plurality of rigid second sections, each second section including a pair of second elements and a second cross member, said second element including
 1. a first piece having an eye at a first end and having the other end joined to the second cross member which maintains said second elements approximately parallel to one another at said predetermined spacing therebetween, the length of said first piece being approximately equal to the length of said first element, a first offset extending a predetermined inward distance at said other end of said first piece, said first piece being joined to said second cross member through this offset, this offset being approximately equal to the first offset of the first element, and a second offset at said first end of said first piece, the magnitude thereof being approximately equal to the second offset of said first element, and
 2. a second piece rigidly connected to the first piece, said second piece having a base for engaging the wall of said building and providing a bearing surface thereagainst, and two sides, the sides forming obtuse angles with said base and being rigidly connected to the first piece; c. alternate first and second sections being connected together as a chain of sections by first and second pairs of pivoted coNnections, the eyes of the first pieces of second sections receiving the first cross members of first sections to form the first pairs of pivoted connections, the eyes of the first elements receiving the cross members of second sections to form the second pairs of pivoted connections; d. said first and second cross members comprising inflexible pieces having lengths approximately equal to the predetermined spacings between the respective pairs of elements; e. covering means rigidly connected to and covering each respective cross member, said covering means having a tread surface providing a ladder step, said covering means comprising
 1. a supporting member rigidly connected to the respective pair of elements, parallel to the cross member therebetween but spaced from the cross member by a gap,
 2. a covering member hollowed out for receiving the supporting member and the adjacent cross member, and
 3. fastening means passing through said gap and rigidly connecting the covering member to the respective section, and f. means for securing the chain of sections to said building.
 2. the other end of each first element being joined to said first cross member, which maintains said first elements approximately parallel to one another at a predetermined spacing therebetween,
 2. a second piece rigidly connected to the first piece, said second piece having a base for engaging the wall of said building and providing a bearing surface thereagainst, and two sides, the sides forming obtuse angles with said base and being rigidly connected to the first piece; c. alternate first and second sections being connected together as a chain of sections by first and second pairs of pivoted coNnections, the eyes of the first pieces of second sections receiving the first cross members of first sections to form the first pairs of pivoted connections, the eyes of the first elements receiving the cross members of second sections to form the second pairs of pivoted connections; d. said first and second cross members comprising inflexible pieces having lengths approximately equal to the predetermined spacings between the respective pairs of elements; e. covering means rigidly connected to and covering each respective cross member, said covering means having a tread surface providing a ladder step, said covering means comprising
 2. a covering member hollowed out for receiving the supporting member and the adjacent cross member, and
 2. The ladder of claim 1 wherein the securing means comprises: a. a pair of flexible members; b. means for connecting one end of each of the flexible members to the building; and c. means for connecting the other end of each of the flexible members to one end of the chain of sections.
 3. The ladder of claim 2 wherein said flexible members are comprised of two equal lengths of chain.
 3. fastening means passing through said gap and rigidly connecting the covering member to the respective section, and f. means for securing the chain of sections to said building.
 3. a first offset extending a predetermined inward distance at said other end, said first element being joined to said first cross member through this offset, and
 4. a second offset at said first end of said first element, said second offset extending inwardly a different distance than the first offset; b. a plurality of rigid second sections, each second section including a pair of second elements and a second cross member, said second element including
 4. The ladder of claim 3 wherein the means for connecting one end of the flexible members to the building comprises: a. an anchor plate having at least two sides approximately perpendicular to one another to permit said sides to be connected to two surfaces of said building; and b. means rigidly connected to said plate for accepting one link of each of said chains thereby securing said chains to the plate.
 5. The ladder of claim 4 wherein the other end of the chain of sections includes a handle rigidly connected thereto.
 6. The ladder of claim 5 wherein all the first and second elements, the cross members and the handle are formed of a wire rod material.
 7. A ladder foldable for storage inside a building and extendible along a wall of the building to permit egress therefrom, the ladder comprising: a plurality of generally U-shaped sections, each section including two parallel side rails which are spaced apart a predetermined distance by a cross member that is connected between them, each side rail having a longitudinal axis and two ends, each side rail having an inward offset adjacent each end thereof which positions the respective rail end inwardly of the longitudinal axis of the rail, the cross member of each section being secured to first ends of the rails respective of the section, inwardly of the longitudinal axes thereof, the cross member being no longer than the predetermined distance by which said rails are spaced, the other end of each rail presenting an eye, the eye being positioned inwardly of the longitudinal axis of the rail by the offset adjacent said other end, the inward offsets of the respective ends being of different inward extents, each eye having a center which is offset perpendicularly from the plane of said U-shaped section, said sections being connected together serially to form a chain, the cross member of each section being pivotally journaled in the eyes of the next adjacent section, the distance between the side rails being the same for all sections so that the longitudinal axes of the pairs of side rails of the respective sections are substantially colinear with one another when the ladder is extended, the pivotal connections between adjacent sections lying inwardly of the axes of the rails by reason of said inward offsets, each said section in the chain being so oriented that when the ladder is extended the eyes of the rails thereof are offset perpendicularly in the opposite direction from the eyes of the rails of the adjacent section, every other section of said chain having a standoff bracket which is connected to the side rails thereof, each standoff bracket having a base for engaging the wall of said building and for providing a bearing surface thereagainst, and two sides, the sides forming angles with the base and being rigidly connected to respective rail inwardly of the longitudinal axis thereof, and means for hanging the chain of sections from said building. 